Method for electrolytic manufacture of titanium and aluminum



United States Patent 3,213,007 METHOD FOR ELECTROLYTIC MANUFACTURE OF TITANIUM AND ALUMINUM Kenji Nakano, 41 Namiuchi-machi, Wakamatsu, Japan No Drawing. Filed Mar. 9, 1962, Ser. No. 178,586 2 Claims. (Cl. 204-105) This invention relates to an electrolytic production of metals such as titanium and aluminum, which heretofore has been very diflicult. More particularly, the present invention is concerned with a process for providing elemental metals-or alloys from salts of the above-mentioned metals economically and easily with high purity, wherein metallic salts of such metals are combined with urea or urea derivatives.

Because titanium is excellent in its resistance to oxidation, acid and corrosion and exhibits other desirable physical and mechanical properties, the electrolytic production or electroplating of titanium has been studied by various methods, none of which have proven satisfactory. Krolls method is one of those methods. However, in Krolls method, pure metallic magnesium is melted and caused to react with the vapor of titanium tetrachloride to obtain metallic titanium of sponge form. Therefore, the cost is inevitably high. Furthermore, in an electrolysis of fused salt, recovery of pure metal is very difficult, because the fusion temperature of titanium is very high (above 1700 C.) and very much liable to be combined with N 0 and C. In addition to titanium, no perfect and accepted method has been established for the electroplating of aluminum.

In accordance with the present invention, a novel method of electrolytic production of metals such as titanium and aluminum shows an advance in the art as compared with the usual process referred to above.

Furthermore, the present invention will be detailed in the following. In addition to titanium tetrachloride which is remarkably unstable to Water, metal halides for other metals including aluminum are combined with other inorganic or organic salts, urea or methyl urea, ethyl urea, diethyl urea, urethan and other basic substances having CONH or CH NH radicals to obtain electrolytic raw materials which are fusible at relatively low temperatures. Such additive compounds are relatively stable to water, i.e., they are fusible at relatively low temperatures, and moreover, they may be subject to electrolysis without causing hydrolysis to occur. After the electroconductivity has been increased by a large amount of urea, or alkali metal halides, alkaline earth metal salts or organic or inorganic acids, if such additive compounds are directly subjected to fusion electrolysis at a temperature from 50 to 200 C., deposition will occur on cathode. On the other hand, the additive compounds are similarly diluted with methanol, ethanol, glycol, glycerine, glycinethyl ester, formamide or other organic, inorganic solvent or water. Similarly, such additive compounds are subjected to non-aqueous solution or aqueous solutionelectrolysis at ordinary temperatures or below 100 C., after added with alkali metal, alkaline earth metal, ammonium salts or organic or inorganic acids. Further, in the electrolysis, when mercury is used for cathodes and graphite for anodes, then amalgam is formed. Then when mercury is evaporated as in an ordinary practice, metal powders of various metal mixtures with a higher concentration of amalgam can be obtained by adding mercuric chloride.

In the following, the present invention will be described in connection with the following examples embodying the invention. Inasmuch as numerous modifications may be possible it is of course understood that the present invention is by no means limited by the examples, but

rather the spirit and scope of this invention is to be interpreted from the appended claims.

EXAMPLE 1.PREPARATION OF ELECTROLYTIC SOLUTION (A) Electrolytic solution for titanium 635 gm. of urea was received in a 2 litre beaker, and 250 gm. of methanol was poured thereinto, to such an extent that surfaces of urea are just moistened slightly. Thereafter, the resulting material was cooled under stirring, while 500 gm. of titanium tetrachloride was gradually dropped into the beaker. Then, the titanium tetrachloride and urea reacted at once and a slightly yellowish to a transparent additive compound Ti (NH CONH 4Cl was produced. This was difiicult to be submitted to bydrolysis with water, and also easily soluble to methanol, ethanol, glycol and glycerin and other organic, inorganic solvents.

(B) Electrolytic solution for aluminum Similarly as in the case of titanium electrolytic solution, onto 68 gm. of urea, 300 gm. of methanol was poured, with which 50 gm. of exothermic was reacted. The just-mentioned method for titanium electrolytic solution may be applied for salts of other metals.

EXAMPLE 2.-ELECTROLYIC OPERATION (A) 23 gm. of titanium electrolytic solution obtainedby the process described at (A), Example 1, was diluted with 45 gm. of anhydrous methanol, and the electrolysis was effected with a copper cathode, a graphite anode and a blanket diaphragm used. The transparent titanium salt solution was reduced to trivalent, and silver white to silver grey metallic titanium could be deposited on the cathode. In this case, not only methanol, but also calcium chloride, barium bromide, calcium bromide and sulfuric acid may be used; inorganic and organic solvents as well as excess urea may also be used.

With the above-mentioned electrolysis conditions, the

following example was brought about:

Anode Graphite.

Cathode 2.2 cm. x 3 cm. copper plate. Temperature 5060 C.

Voltage between poles 8 volts.

Current 0.5-0.8 amp.

Time for electrolysis 30 min.

Electrodeposition Anode opposite face 42-47 Furthermore, with the Ti(NH CONH Cl alcohol solution, or an aqueous solution or the aqueous solution admixed with ammonium fluoride or extremely slight amount of sugar decomposition product, a 0-20 w./v. percent sulfuric acid solution was used. With a mercury cathode an anal-gam was obtained with the concentrated aqueous solution being added to mercuric chloride and with graphite being used for the anode and cathode, electrolysis was effected and 3.10% titanium amalgam was obtained. In this case, when salts of copper, aluminum, cobalt, nickel, lead, chrome were added instead of mercuric chloride, similarly various alloys could be deposited.

(B) Using half quantity, i.e. cc. of aluminum, the electrolytic solution from the method described Example 1-(B) was electrolyzed with a blanket diaphragm and a silver white deposition of metallic aluminum was obtained.

Fuirthermore, the above-mentioned electrolysis condition was used for the electrolysis as follows:

Anodes Aluminum plates.

Cathode 1.9 cm. x 4.2 cm. copper plate. Temperature 60-65 C.

Voltage between poles 8 volts.

Current 0.1 amp under.

Deposition Anode: opposite faces 11.5 p. Deposition Anode: rear face 3.5 ,u.

As described in the foregoing description, according to this invention, the production of metals including titanium and aluminum can be made easily and economically from fused salt in a non-aqueous solution or aqueous solution, which have heretofore been considered too difficult.

What I claim is:

1. A method for the electrolytic manufacture of titanium metal comprising reacting the salt of said metal with urea to obtain an electrolytic solution which is stable to water, diluting the electrolytic solution with an aqueous solvent, and subjecting the diluted solution to an electrolysis process having the following parameters:

Anode Graphite.

Cathode 2.2 cm. X 3 cm. copper plate. Temperature 5060 C.

vVoltage 8 volts.

Current 0.5-0.8 amp.

Time 30 minutes.

Electrodeposition Anode opposite face 42-47 ,u.

2. A method for the electrolytic manufacture of aluminum metal comprising reacting the salt of said metal with urea to obtain an electrolytic solution which is stable to Water, diluting the electrolytic solution with an aqueous solvent, and subjecting the diluted solution to an electrolysis process having the following parameters:

References Cited by the Examiner UNITED STATES PATENTS 2,692,850 10/54 Safranek et al. 204-39 2,703,752 3/55 Glasser et al 20464.1 2,818,375 1'2/57 Schnable 204-39 OTHER REFERENCES 5 Creamer et al.: Bureau of Mines Report No. 5093, U.S.

Dept. of Interior, December 1954, pp. 7 and 8, 204-39.

WINSTON A. DOUGLAS, Primary Examiner.

JOHN R. SPECK, JOHN H. MACK, Examiners. 

1. A METHOD FOR THE ELECTROLYTIC MANUFACTURE OF TITANIUM METAL COMPRISING REACTING THE SALT OF SAID METAL WITH UREA TO OBTAIN AN ELECTROLYTIC SOLUTION WHICH IS STABLE TO WATER, DILUTING THE ELECTROLYTIC SOLUTION WITH AN AQUEOUS SOLVENT, AND SUBJECTING THE DILUTED SOLUTION TO AN ELECTROLYSIS PROCESS HAVING THE FOLLOWING PARAMETERS:
 2. A METHOD FOR THE ELECTROLYTIC MANUFACTURE OF ALUMINUM METAL COMPRISING REACTING THE SALT OF SAID METAL WITH UREA TO OBTAIN AN ELECTROLYTIC SOLUTION WHICH IS STABLE TO WATER, DILUTING THE ELECTROLYTIC SOLUTION WITH AN AQUEOUS SOLVENT, AND SUBJECTING THE DILUTED SOLUTION TO AN ELECTROLYSIS PROCESS HAVING THE FOLLOWING PARAMETERS: 